the 'if...else' is not checking any other conditions, directly skipping to last 'else' statement

i,m calling a JavaScript function to change an image by using if..else statement to change its source. but it directly skips to last else statement, so the image only keeps swapping between first & last image

JavaScript function:

function myfunction2() {
    var image = document.getElementById("image");
    //iterartion 1
    if (image.src == "img1.jpg") {
        image.src = "img2.jpg";
    } else if (image.src == "img2.jpg") {
        image.src = "img3.jpg";
    } else if (image.src == "img3.jpg") {
        image.src = "img4.jpg";
    } else if (image.src == "img4.jpg") {
        image.src = "img5.jpg";
    } else if (image.src == "img5.jpg") {
        image.src = "img1.jpg";
    } else {
        image.src = "img2.jpg";
    }
}

html code:

<div id="image-slider">
            <img src="img1.jpg" id="image">

            <div id="left-holder">
            <img onclick="myfunction2()" src="arrow-left.png" height="49px" width="49px" class="left"/>
            </div>

            <div id="right-holder">
            <img  onclick="myfunction2()" src="arrow-right.png" height="49px" width="49px" class="right"/>
            </div>
</div>

what am i doin wrong here? plz help.